Abrading aid containing paraffin and an inhibitor

ABSTRACT

A direct externally applied grinding, abrading and cutting aid for tools which includes a vehicle or carrier of a suitable matrix softer than the cutting material and which will readily adhere thereto without chipping while the tool is in motion. Dispersed within the matrix is a halogen salt or the like which includes hydrocarbons, chlorides, fluoborates, fluorides and various sulfides. These materials were selected on the basis that they sublime or decompose at temperatures below those that would metallurgically damage the metal workpiece. This aid is applied directly to the tool, as for example, to a coated abrasive and may be reapplied as often as is necessary, thus increasing both the life of the tool, its cutting rate, total metal removal, and its efficiency in addition to lowering the temperature of the material being cut. In addition, there is disclosed an automated system for maintaining the workpiece at a selected temperature through the controlled application of the aid.

United States Patent Wirth [76] Inventor: John J. C. Wirth, 98 Ponus Ave.,

Norwalk, Conn. 06850 [22] Filed: July 26, 1971 [21] Appl. No.: 166,093

[52] US. Cl 51/306, 51/307, 252/31, 252/59 [51] Int. Cl. 1324b 1/00, ClOm 3/06 [58] Field of Search 51/293, 295, 296, 303, 51/304, 307, 308; 106/10, 11; 252/31, 24, 59

[56] References Cited UNITED STATES PATENTS 2,016,892 10/1935 Claruoe 51/293 2,849,324 8/1958 Cox 106/10 3,269,813 8/1966 Kibbey r .1 51/307 3,400,017 9/1968 Huebner 51/307 3,541,739 11/1970 Bryon et a1. 51/295 3,595,634 7/1971 Sato .1 51/295 Primary E amz'ryer gc r ald I Arnold Attorney, Agent, or Firm-Ernest F. Weinberger [57] ABSTRACT A direct externally applied grinding, abrading and cutting aid for tools which includes a vehicle or carrier of a suitable matrix softer than the cutting material and which will readily adhere thereto without chipping while the tool is in motion. Dispersed within the matrix is a halogen salt or the like which includes hydrocarbons, chlorides, fluoborates, fluorides and various sulfides. These materials were selected on the basis that they sublime or decompose at temperatures below those that would metallurgically damage the metal workpiece. This aid is applied directly to the tool, as for example, to a coated abrasive and may be reapplied as often as is necessary, thus increasing both the life of the tool, its cutting rate, total metal removal, and its efficiency in addition to lowering the temperature of the material being cut. In addition, there is disclosed an automated system for maintaining the workpiece at a selected temperature through the controlled application of the aid.

3 Claims, 10 Drawing Figures TEMPE/24 Twas l/ME WORKP/ECE WASP/42L a V 5527 .jPEED 361w JFM low- TEMPE/e4 70/25 WORKP/E6E Mm 19/0 HPPL/ED 0. hams 5a. w.

I I I I l 0 If 3 $0 5 MET/9L FEW/mm [/v 695/145 PAIENIEnsEP 3:914

sum 1 or 10 l l I 77/145 [M All/V0756 I NVEN TOR.

PATENTLU 31974 3.833.346

saw o7nr1o INVENTOR. fi/M/ J 6. IV/RU/ ABRADING AID CONTAINING PARAFFIN AND AN INHIBITOR FIELD OF THE INVENTION The present invention relates to abrasive and cutting articles and more particularly pertains to novel externally applied aids for substantially increasing cutting efficiency at reduced operating temperatures without deleteriously affecting the characteristics of the metal being abraded.

In the field of abrasives and cutting, it has long been the general practice to employ a variety of grinding aids in order to improve the overall efficiency. These aids include solids, liquids and gases and serve generally to improve conditions within the restricted area of cut ting. One common approach has been to incorporate within the metal to be machined small quantities of sulfur and or lead so that under the high temperatures encountered favorable chemical reactions take place to provide improved machinability. These effectively form low shear strength solids at the surface. A similar formation can be attained by the addition of oils containing sulfur, chlorine and phosphorus to provide low friction films between the cutting surface and the workpiece to reduce pressure welds and galling. It has been found, however, that in the case of coated abrasives, high melting point waxes must be employed to reduce the grain penetration. The most commonly used grinding aids are in the form of liquids and include water, soluble oils, mineral and fatty straight cutting oils, as well as those that are sulfurized and chlorinated. The latter, as stated above, form low friction films which may be effective for certain steels but are not entirely useful for the present super alloys and titanium. Greases and hard waxes are not effective except in reducing the loading of relatively soft metals such as aluminum, brass, etc.

The described aids have been used on standard materials with varying degrees of success but have been virtually useless in the field of space-age super alloys which are heat resistant, high temperature, high strength alloys having low thermal conductivity. Abrasive products and cutting tools are employed essentially to remove metal stock and generally fail to accomplish this end due to the loss of cutting effectiveness long before all or even a significant portion of the cutting tool surface has been consumed. In the majority of cases involving high temperature alloys, one of the most prominent causes of failure resides in the fact that the freshly exposed or cut surface is highly reactive and this nascent area is subject to the formation of a weld juncture which, in turn, exerts an extremely high shear force against the cutting material. It is also quite clear that the welding becomes far more acute under conditions of high temperature. Although these inherent problems are encountered in all forms of cutting, they are particularly troublesome in the case of coated abrasives where the surface is not renewed as in grinding wheels and such. Since coated abrasives essentially rely on only a single layer of abrading particles, it has been found, to date, that little can be done to improve their efficiency beyond a specific point. Attempts to externally improve their cutting ability have included the use of grease sticks, oils and other lubricants during the cutting operation. Also, attempts have been made by various manufacturers to incorporate aids into abrasive belts and grinding wheels in a permanent, fixed manner during fabrication without any possible selective application thereafter. These have, however, proved effective only to a very limited degree and the disadvantages, inconvenience and expenses have limited their general use.

In addition to the problem of welding and loading, there exists what is known as glazing, wherein the workpiece particles form a glaze and cover the irregular cutting surfaces of the abradant, thus diminishing its useful life and metal removal rate. This is true for super alloys and it has been found that lubricants retard but do not prevent glazing. It appears that there is a direct inter-relationship between the foregoing factors and temperature. Factors which normally tend to elevate the temperature at the work surface (interface) also promote welding, chemical reactions, glazing, generation of internal workpiece stresses, as well as burning of the workpiece surface, which adversely affect the metallurgical structure at the surface. Such affects include forming brittle Martensite layers in heat treated steels and precipitation of constituents in age hardenable alloys. These factors are present in all cutting techniques but they are substantially more severe in the super alloys due to their high temperature and lowthermal conductivity characteristics.

In the precision finishing of certain metal structures such as high speed turbine vanes, it is essential that fine control be continually exercised on the part of the operator during the entire operation. In general, cutting necessitates that relatively high pressure be applied between the abradant and the workpiece, as is the case, for most metals, and this presents an inherent loss of control on the part of the operator with an attendant loss of precision. By permitting the abrading to take place at a substantially reduced applied pressure, it has been found that the resulting finished surface can be held to previously unattainable standards without any loss of efficiency, time and expense. One device employed for this type of finishing is a flap-wheel which is essentially a rotatable hub, radially carrying a plurality (800-1000) of strips of cloth backed abrasive coatings. These wheels are used in blending, namely, the removal of minute protuberances and scratches from a surface and the feathering of edges. The external application of the inventive aid described hereinafter to the abrasive faces of the flap-wheel has allowed the operation to be performed at substantially lower pressures and thereby providing extremely accurate and precise finishes. I

The present inventive abrading and cutting aids fill this need and are especially effective for the class of metals and alloys that are now coming into general use.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide an externally applied abrading and cutting aid that has all the advantages of similarly employed prior art devices and none of the above described disadvantages. To attain this, the present invention provides an aid which comprises in general, a carrier or matrix softer than the workpiece which has dispersed therein one or more halogen or alkali metal salts, including potassium fluoborate, bromine, chlorine, iodine, sulfur, cryolite and specific non halogen materials such as sodium nitrates and nitrites which are particularly effective in increasing the rate of removal of super alloys. The selection of these compounds was made so that sublimation or decomposition occurs in abrasion. The frictional heat of abrasion is principally dissipated in the sublimation or decomposition process, thereby maintaining a substantially lower temperature at the workpiece.

An object of the present invention is to provide a relatively inexpensive, highly efficient cutting and abrading aid which may be applied externally to prolong the useful life and efficiency of a tool.

Another object of the present invention is the provision of a grinding aid which may be applied to coated abrasive products and thereby inhibit weld juncture, glazing, burring and the formation of difficult to remove products of chemical reactions while preventing the generation of excessively high temperatures.

Still another object is to provide an aid for the abrading of high temperature, high strength and low thermal conductivity metals and alloys which will increase the metal removal rate over an extended uniform period.

FIG. 1 is a graph indicating the metal removal rate for various abrading aids wherein the workpiece is WASPALOY and the speed 36OOSFM;

FIG. 2 is a graph similar to that of FIG. 1 except the speed is 7200 SFM;

FIG. 3 is a graph indicating the metal removal rate for various abrading aids wherein the workpiece is a Titanium alloy and the speed is 3600 SFM;

FIG. 4 is a graph indicating the metal removal rate for an aid wherein the workpieces are HASTELLOY and L605 alloys and the speed is 3600 SFM;

FIG. 5 is a graph indicating the metal removal rate for an aid wherein the workpiece is an aluminum alloy;

FIG. 6 is a graph indicating the temperature of the WASPALOY workpiece with and without an aid applied to the abrasive during metal removal;

FIG. 7 is a block representation of an automated temperature control system for a workpiece which is being abraded with an aid of this invention;

FIG. 8 is a graph indicating the metal removal rate for an aid wherein the workpiece is carbon steel; and

FIG. 9 is a graph indicating the metal removal rate for a nonhalogen aid wherein the workpiece is a Titanium alloy; and

FIG. 10 is a graph indicating the metal removal rate for an aid wherein the workpiece is stainless steel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With the advent and introduction of high strength, high temperature and low thermal conductivity super alloy metals, it has been found by those responsible for machining these metals, that extensive problems are inherent due to the metallurgical properties thereof. Machining of these super alloys, which include WAS- PALOY, INCONEL, RENE 4l, HASTELLOY and other high nickel base alloys, as well as a cobalt base alloy L650 and aluminum die casting alloys suchas alloys 85 and 360 extensively used in the aerospace industry, as well as titanium alloys, have proven to be most difficult in all cutting operations and particularly in those employing abrasive techniques for removal of the metal. Galling, glazing and welding constitute the most severe problems while the high temperatures generated tend to degrade both the surface finish as well as the surface integrity and induce. stress therein. The

term cutting tool used herein is broadly defined as any device or material which will progressively remove portions of the workpiece, as for example, abrasive wheels, discs and belts, files, drills, milling tools, cutters, etc. Due in part to their structural and physical characteristics and wide use and acceptance, coated abrasives present the most critical problems of the cut ting tool class. Although measurements and analysis have been conducted on a wide variety of tools, coated abrasives have been selected as representative of the class since it was found that the application of various aids thereto and the results thereof indicate that if such aids are beneficial for coated abrasives, they likewise improve the cutting ability of the others in the class. It is for this reason that the examples described hereinafter are all directed toward coated abrasives. The two most difficult to handle super alloys, namely WAS- PALOY and a titanium alloy, were selected as workpieces, in addition to HASTELLOY and aluminum die cast alloys.

Numerous laboratory studies were conducted to both measure and evaluate abrasive belt efficiencies under standard and controlled conditions. Determinations were also made of the surface temperatures in addition to the rate of metal (workpiece) removal. The abrasives selected were resin-bonded 60 grit aluminum oxide and silicon carbide. The test equipment consisted essentially of a coated abrasive belt mounted around a contact wheel. A dual speed drive was coupled thereto for selectively varying the belt speed in terms of surface feet per minute (SFM). The workpiece infeed pressure was adjustable through deadweight loading against the rubber contact wheel whose Durometer hardness was between and 90. With fixed values of belt tension, the belt speed was ascertained with a tachometer and the resulting stock removal was measured on a sensitive balance scale at specific times during abrasion. The test parameters were held constant and it was initially found that the cumulative amount of stock removed for short time intervals was proportional to that for longer periods and therefore the evaluations were conducted over longer time intervals. Representative belt speeds, as well as pressure, were selected to simulate actual industrial conditions.

In general, the novel cutting aid of this invention includes two basic components, namely, a vehicle or car rier in the form of a suitable matrix; which is physically softer than the cutting portion of the tool so as not to abrade it while being able to readily adhere to the moving tool without chipping or being centrifugally dislodged therefrom. The other constituent is any one of the presently known abrading aids or inhibitors which, as a class, are generally designated as halogen and alkali salts, halogenized hydrocarbons, in addition to those not previously known or used but disclosed in the following examples, which also include nonhalogens. The carrier can be almost any formulation ranging in form from a liquid to a solid and includes a variety of matrix materials, but not limited to polymerics, polymers, waxes, shellacs, paraffin and petroleum jelly and can include powdered metals with plastics. The latter are particularly useful over wide surfaces where a rigid matrix is necessary for the external application. It is evident, of course, that the two basic components must be physically and chemically compatible, and the one must be dispersible in the other. In general, the matrix is in a form so as to be readily available to accept the inhibitor; as for example, as a liquid in at least one state as by heating or chemical action. The aid was applied in all the tests at a rate less than 0.5 grams per square inch.

In a first series of tests, a typical, representative steel based super alloy, namely WASPALOY, was selected as the workpiece and although various cutting tools were employed, it was ascertained that the results were in conformance with those obtained where the abrading tool was an abrasive belt. A 60 size grit aluminum oxide belt was employed since it is the type generally used for abrading WASPALOY and operated at two speeds (3600 and 7200 SFM). Metal removal rates were first determined for a standard commercially available externally untreated belt and these were then compared to the rates of the belts to which the grinding aids were applied. Prior evaluations have indicated that the relative improvement in removal rate is, for the most part, dependent on the specific inhibitor or additive, although in certain instances there appears to be some synergistic effects between the inhibitor and the vehicle. It should be borne in mind that the results disclosed herein have been found, in general, to be representative. FIG. 1 shows the metal removal in grams plotted against time at a belt speed of 3600 SFM and a pressure of 16 poundsper square inch (psi). Curve indicates the removal for the as received or unaided belt to which all the other curves or results should be compared. Percentage increases (PI) of metal removal in 5 minutes were also calculated and disclosed as compared to the uncoated belts.

EXAMPLES OF AIDS Curve ll a commercially available grease stick weighing 86 grams was melted and while in such a liquid state there was uniformly dispersed therein approximately 86 grams of ammonium chloride (NH Cl) and resulting solid was rubbed over the belt to provide a uniform externally applied coating. It is further evident that the use of grease, wax or paraffin alone is totally ineffective. PI -(47 percent) Curve l2 to a melted composition of 45 grams of paraffin and 5 grams of petroleum jelly, there was added 50 grams of cryolite (Na AlF and uniformly dispersed therein and again the solidified result rubbed on the belt. PI 19 percent Curve l3 vehicle melted composition 90 grams paraffin and 10 grams petroleum jelly.

inhibitor 100 grams ammonium chloride (NI-I Cl) uniformly dispersed in vehicle. Pl 41 percent Curve 14 vehicle melted composition 45 grams paraffin and 5 grams petroleum jelly.

inhibitor 50 grams of potassium fluoborate (KBF uniformly dispersed in vehicle. Pl 34 percent Curve 15 vehicle melted composition 105 grams paraffin inhibitor 30 grams of potassium fluoborate (KBF 30 grams of ammonium chloride (NI-I Cl), 30

grams of ammonium fluoborate (NH BF grams of cupric chloride (CuCl and 20 grams of cupric sulfide (CuS). PI 55 percent Summarizing the results, it is evident that as a vehicle the commercially available grease stick (curve 11), degrades the abrading ability of the belt when compared to another vehicle (curve 13) employing the identical inhibitor and that the addition of a vehicle namely paraffin and petroleum jelly in combination with the Cryolite provides an improved aid.

Attention is now directed to Pat. No. 3,256,076 wherein it is stated that although aids in general and those set forth therein improve the cutting efficiency of grinding wheels, when applied to the binder of coated abrasive products, are essentially of no value. The specification continues with the statement that although the aids disclosed are known for (use with) grinding wheels, they were never previously employed for or on coated abrasives. The disclosure teaches the application of a heat decomposable polymer film to the abrading surface and is applied during fabrication as a oneshot treatment. There can not be any subsequent control nor can the film be selectively applied by the user and does not encompass or function in conjunction with a vehicle.

Additionally, in view of the results indicated by curves l3 and 14, it is clear that the vehicle employed provides a synergistic effect. It is quite evident that the aforementioned effect is best illustrated by the superior results indicated by curve 15.

The parameters of a second series of tests were identical to those of FIG. 1 except that the belt speed was increased to 7200 SFM.

EXAMPLES OF AIDS Curve 20 an as received untreated belt. Curve 21 vehicle melted composition 190 grams paraffin, 30 grams petroleum jelly.

inhibitor 200 grams potassium fluoborate (KBF PI 93 percent Curve 22 vehicle melted composition of grams paraffin and 10 grams petroleum jelly.

inhibitor grams ammonium chloride (NI-l Cl).

PI 100 percent Curve 23 vehicle melted composition of 140 grams paraffin and 25 grams petroleum jelly.

inhibitor 140 grams of potassium fluoborate (KBF and 100 grams of ammonium chloride (NH Cl). PI l67 percent Summarizing, it is clear that with an increase in belt speed, the metal removal is relatively, proportionally increased. This observation has been verified by other investigators. It has also been observed that increasing the proportion of a single or combination of inhibitors beyond approximately 50 percent of total does not proportionally increase the effectiveness of the aid except in certain specific instances. One such instance is that exemplified by the results indicated by curve 23.

Referring now to the series of results illustrated in FIG. 3, wherein the workpiece is a Titanium alloy (Ti- 6-Al-4V), belt speed 3600 SFM at a pressure of 7 psi and the abrasive is 60 grit silicon carbide. Curve 32 as received untreated belt Curve 33 commercially available pre-coated treated belt. PI 19 percent Curve 34 vehicle 100 grams of paraffin and 10 grams petroleum jelly.

inhibitor grams of ammonium fluoborate (NH BF PI 38 percent Curve 35 vehicle 100 grams of paraffin and 10 grams of petroleum jelly.

inhibitor 120 grams of cupric chloride (CuCl). Pl

42 percent Curve 36 treated commercially available belt manufactured by Clover Manufacturing Co., under the tradename THERMABLATE and subsequently coated with:

vehicle 45 grams of paraffin and grams of petroleum jelly.

inhibitor 50 grams of potassium fluoborate (KBF,).

PI 60 percent Curve 37 vehicle 45 grams of paraffin and 5 grams of petroleum jelly.

inhibitor 50 grams of potassium fluoborate (KBF PI 100 percent From the foregoing, it is evident that the addition of the inventive externally applied aids improves the metal removal for both untreated belts and those previously treated by the manufacturer to increase the metal removal and belt life for both types of abrasives.

Refer now to the test results illustrated in FIG. 4 the workpieces were HASTELLOY C276, a high temperature nickel base alloy, and L605 alloy, which is a cobalt base alloy. The belt speed was 3600 SFM at a pressure of 16 psi, and the abrasive was 60 grit resin bond aluminum oxide; the examples are as follows:

Curve 40 as received untreated belt on HASTEL- LOY.

Curve 41 as received untreated belt on L605 alloy.

Curve 42 vehicle 95 grams of melted paraffin. inhibitor 30 grams potassium fluoborate (KBF 25 grams cryolite (Na AlF 30 grams of ammonium chloride (NI-I Cl), grams of sulfur and 25 grams ammonium fluoborate (Nl-I BF on HASTEL- LOY. PI 152 percent Curve 43 vehicle 95 grams of melted paraffin.

inhibitor 30 grams potassium fluoborate (KBF 25 grams cryolite (Na AlF -30 grams of ammonium chloride (NH CI), 10 grams of sulfur and 25 grams ammonium fluoborate (Nl-I BF on L605 alloy. PI 146 percent From these curves and the extraordinary percentage increase in metal removal, it is clear that the combination aid employed is of superior quality and performance.

Refer now to FIG. 5 wherein the workpiece was a die casting aluminum alloy designated number 360 and containing 9.5 percent silicon and 0.5 percent magnesium. The abrasive was 60 grit resin bond aluminum oxide at a speed of 3600 SFM and a pressure of 8 psi, with the results as follows:

Curve 50 as received untreated belt Curve 51 vehicle 95 grams of melted paraffin.

inhibitor 30 grams potassium fluoborate (KBF 25 grams cryolite (Na AIF 30 grams of ammonium chloride (NI-I Cl), 10 grams of sulfur and 25 grams ammonium fluoborate (NI-I BF PI 157 percent.

Refer now to FIG. 8 wherein the workpiece was plain carbon steel in the form of a bolt and the abrasive was 60 grit resin bond aluminum oxide at a speed of 3600 SFM and a pressure of 10 psi with the following examples:

Curve 80 as received untreated belt Curve 81 vehicle 100 grams of paraffin.

inhibitor 30 grams potassium fluoborate (KBF grams cryolite (Na AlF 30 grams ammonium chloride (NH CI), 10 grams of sulfur, grams of ammonium fluoborate. PI-l05 percent.

The effectiveness of the aid when used on carbon steel is clearly indicated from the above curves.

In certain abrading applications, it is not desirable to employ an aid which is of the halogen variety and applicant has therefore included the aid in the examples that follow wherein the workpiece was a titanium alloy (Ti- 6Al-4V). The abrasive was 60 grit resin bond silicon carbide at a speed of 3600 SFM and at pressures of 4 and 8 psi (see FIG. 9).

Curve as received untreated belt operated at 4 psi Curve 92 as received untreated belt operated at 8 psi Curve 91 vehicle 50 grams of paraffin. inhibitor 50 grams of sodium nitrate (NaNO operated at 4 psi. PI 57 percent Curve 93 vehicle 50 grams of paraffin. inhibitor 50 grams sodium nitrate (NaNO operated at 8 psi. PI 98 percent Tests wherein sodium nitrite (NaNO was substituted for the nitrate form resulted in similar values of PI. Thus, there is disclosed a non halogen aid which is of superior value. This aid was also applied to a super grade stainless steel as shown in FIG. 10 wherein the steel was Greek Ascoloy Stainless Steel, heat treated to a Rockwell hardness of 34. The speeds were 3600 and 7200 SFM while pressures of 4 and 8 psi were employed with a 60 grit resin bond aluminum oxide abrasive.

Curve 100 as received untreated belt, 3600 SFM and 4 psi.

Curve 101 vehicle 50 grams of paraffin.

inhibitor 50 grams of sodium nitrate, 3600 SFM and 4 psi. PI 13 percent Curve 102 as received untreated belt, 3600 SFM and 8 psi.

Curve 103 vehicle 50 grams of paraffin.

inhibitor 50 grams of sodium nitrate 3600 SFM and 8 psi. PI 56 percent Curve 104 as received untreated belt 7200 SFM and 4 psi.

Curve 105 vehicle 50 grams of paraffin.

inhibitor 50 grams of sodium nitrate, 7200 SFM and 4 psi. PI 124 percent SURFACE WORKPIECE TEMPERATURES (See FIG. 6) measured with a highly sensitive thermocouple indicate an average reduction in temperature of approximately 390F. after 1 minute of continuous abrasion.

It is postulated that the effect or operation of the aid is such that the heat of sublimation and decomposition lowers the workpiece surface temperature due to the fact that the energy necessary in this process is derived from the workpiece itself, thereby preventing the breakdown of the abradant and any welding which requires extremely high temperatures. Additionally, the gases generated provide or maintain a nascent workpiece surface. The results indicated in FIG. 6 clearly show that for a typical aid including fluoborate that after 1 minute the workpiece (WASPALOY) temperature levels off to about 650F, while the unaided abrasion allows the temperature to exceed 1000F.

It is clear from the foregoing that with the application of the aid the temperature of the workpiece is maintained at a substantially lower temperature than when untreated abradants are employed. An operator could, by observing the workpiece, have a general knowledge as to its relative temperature, but he cannot ascertain whether the operating temperature will damage the workpiece since these temperatures are critical. Additionally, the operator could be advised of the workpiece temperature through the use of an indicating thermocouple but under these conditions he must not only be skilled in the operation, but must also divert his attention, thus lowering his efficiency and the quality of the final finished product. To provide an accurate, dependable and efficient application of the aid, the automated system of FIG. 7 has been devised. 1n operating on a workpiece, the typical structure contemplates a pair of rollers 70 and 71, one of which is driven, having looped thereabout a coated abrasive belt 72, which rotates past the workpiece 73. Where a grinding wheel is employed, the aid is applied to the wheel directly and the rollers are eliminated. Disposed on the opposite side of the belt 72 is a pressure roller 74 so that as the workpiece is pressed against the belt, the pressure roller provides or acts as a backing member. A bolometer, or any suitable temperature sensor, 75, is located proximate the workpiece surface which is being abraded. It need not be in contact-therewith since it is sensing the radiated energy. The electrical output of the bolometer is fed into amplifier 76 which increases the electrical signal proportional to the workpiece temperature, and to a level sufficient to control the operation of the application drive means 77. The application means can, in its simplest form, be a motor whose angular displacement is dependent on the input voltage or current level. The angular displacement is converted into a linear motion by any well known mechanical structure (not shown) such as a rack and pinnion and the output derived via reciprocal output arm 78. The arm extends through bearing opening 79 in support housing 80 and terminates therein at a piston 81 which is free to slide in the housing. The piston is biased against forward motion by a biasing means which in this case constitute springs 82 so that when arm 78 retracts or releases, the piston will return. The upper surface of the piston bears against the rear surface of the aid material 83 which is also confined within the housing and free to slide therein and abut the belt 72 opposite its pressure roller 84. During the abrading of the workpiece, the operator presses the piece into intimate pressure contact with the belt and the temperature thereof rapidly rises. The sensor 75 detects this increased temperature and effectively causes the application means to move the piston toward the belt, resulting in application of the aid 83 to the belt 72. This, thereupon, decreases the workpiece temperature to the limiting value selected via the amplifier or the application means and the pressure between the aid and the belt is relieved. This automated feedback control system remains in operation until the finishing of the workpiece is completed and continually maintains a selected limiting temperature below that which could damage or discolor the workpiece.

Concluding from all of the abovedescribed results and observations from other unreported experiments, the following facts are evident:

OVERALL METAL REMOVAL substantially increased the removal as indicated above.

SURFACE DISCOLORATION none observed for aided belts while excessive discoloration was evident for the workpiece abraded by the untreated belt due to the high temperature generated.

The tabulation set forth hereinafter summarizes the basic results wherein all the factors can be directly compared.

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

TABULATlON OF METAL REMOVAL TESTS AID METAL ABRASlVE BELT METAL PERCENT- REMOVED AGE COMPOSlTlON ABRADED Type Speed Pressure Grams Time INCREASE CURVE SFM PSI Mln.

None Waspaloy 60A1OX 3600 16 1.08 5 Grease stick-l-NH Cl Waspaloy 60A10x 3600 16 0.59 5 47 1 1 Na AlF -l-Paraffin Waspaloy 60A10x 3600 16 1.31 5 19 12 NH,C1+Paraffin Waspaloy 60A10x 3600 16 1.55 5 41 13 KBF.,+Paraffin Waspuloy 60A10x 3600 16 1.48 5 34 14 KBF +NH C1+NH BF cu( :1,+ci1s 4 4 Waspalov 60A10x 3600 16 1.70 5 55 15 None Waspaloy 60A10x 7200 16 1.51 5 20 KBF,+Paraffin Waspaloy 60Al0x 7200 16 2.91 5 93 21 NH Cl+Paraffin Wuspaloy 60A10x 7200 16 3.00 5 100 22 KBF +NH Cl+Paraffin w palov 60A10x 7200 16 4.03 5 167 23 None Ti-6Al-4V 60 SiC 3600 7 0.93 5 32 Comm. Pretreatcd Ti-6A1-4V 60 SiC 3600 7 1.10 5 19 33 NH BF,+Paraffln Ti-6A1-4V 60 SiC 3600 7 1.28 5 38 34 CuCl+Paraftin Ti-6Al 4V 60 SiC 3600 7 1.32 5 42 35 f n on Ti-6Al-4V 60 SiC 3600 7 1.49 5 60 36 KBF +Paraffin Ti-6Al-4V 60 SiC 3600 7 1.94 5 100 37 None Hastclloy 60A10x 3600 16 1.25 5 40 KBF +NaA1F +NH C1 Hastclloy 60A10x 3600 16 3.15 5 152 42 s ffimBRdmmnin L605 60Al0x 3600 16 4.28 5 146 43 None L605 60A10x 3600 16 1.74 5 41 None Al Alloy 360 60A|Ox 3600 8 3.50 4 KBF +Na AlF +NH Cl A1 Alloy 360 A1Ox 3600 8 9.03 4 157 51 None 4 4 Carbon Steel 60A10x 3600 10 6.39 5 KBF +Na AlF 1+S+NH BF l zii ffin 4 4 Carbon Stecl 60A10x 3600 10 13.06 5 81 TABULATlON OF METAL REMOVAL TESTS Continued AID METAL ABRASlVE BELT METAL PERCENT- REMOVED AGE COMPOSITION ABRADED 'l'ypc Speed Pressure Grams Time INCREASE CURVE SFM PSI Min.

None Ti-6Al-4V 60Al0x 3600 4 0.54 90 NaNO NaNO )+Paraf'fin Ti-6Al-4V 60AlOx 3600 4 0.85 5 57 91 None Ti-6Al-4V 60AlOx 3600 8 1.30 5 92 NaNO,(NaNO Ti-6Al-4V 60AlOx 3600 8 2.58 5 98 93 None Greek Ascoloy Stainless Steel 60Al0x 3600 4 1.38 5 100 NaNO NaNO )l-Paraffin Greek Ascoloy Stainless Steel 60AlOx 3600 4 L56 5 I3 101 None Greek Ascoloy Stainless Steel 60AlOx 3600 8 5.57 5 102 NaNO (Nz1NO )+Paraffin Greek Aseoloy Stainless Steel 60AlOx 3600 8 i 8.69 5 56 103 None Greek Ascoloy Stainless Steel 60AlOx 7200 4 3.33 5 104 NaNO; (NaNO Greek Ascoloy 1 Stainless Steel 60Al0x 7200 4 7.47 5 124 105 Paraffin I claim: consists of approxlmately by weight an admixture of:

1. A grinding and cutting externally applicable aid for a tool operating on a metallic workpiece for increasing the efiiciency and lowering the temperature of the workpiece surface during removal thereof which aid consists of approximately by weight an admixture of:

95 grams of paraffin,

30 grams of potassium fluoborate,

grams of cryolite,

grams of ammonium chloride,

10 grams of sulfur, and

25 grams of ammonium fluoborate.

2. A grinding and cutting externally applicable aid for a tool operating on a metallic workpiece for increasing the efficiency and lowering the temperature of the workpiece surface during removal thereof which aid grams of paraffin,

30 grams of potassium fluoborate,

30 grams of ammonium fluoborate,

30 grams of ammonium chloride,

20 grams of cupric chloride, and

20 grams of cupric sulfide.

3. A grinding and cutting externally applicable aid for a tool operating on a metallic workpiece for increasing the efficiency and lowering the temperature of the workpiece surface during removal thereof which aid consists of approximately by weight an admixture of:

50 percent of paraffin, and

50 percent of sodium nitrite. 

2. A grinding and cutting externally applicable aid for a tool operating on a metallic workpiece for increasing the efficiency and lowering the temperature of the workpiece surface during removal thereof which aid consists of approximately by weight an admixture of: 105 grams of paraffin, 30 grams of potassium fluoborate, 30 grams of ammonium fluoborate, 30 grams of ammonium chloride, 20 grams of cupric chloride, and 20 grams of cupric sulfide.
 3. A grinding and cutting externally applicable aid for a tool operating on a metallic workpiece for increasing the efficiency and lowering the temperature of the workpiece surface during removal thereof which aid consists of approximately by weight an admixture of: 50 percent of paraffin, and 50 percent of sodium nitrite. 